OT: Wing loading at the speed of sound

I don't know if it's true or not, but I have heard that story several times on various programs about the experimental aircraft program on the History Channel, so they think that it is.

-- John ___ __[xxx]__ (o - ) --------o00o--(_)--o00o-------

The history of things that didn't happen has never been written - Henry Kissinger

Reply to
The Old Timer
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ISTR reading that in "Air and Space" so one of their authors bought into it. The fuselage certainly looks like a bullet to me.

Bill Banaszak, MFE

Reply to
Bill Banaszak

Yeah, I'll bet you're right about the commercial sims.

It's been a while since I've done any CFD myself, but I trip over some on occasion - usually pressure distros, but not incorporating any dynamics; the latest eyewatering example was some of the animations NASA did for the Columbia mishap analysis. The capability is out there...

Reply to
Rufus

I recall hearing that too, but I can't remember where...

Reply to
Rufus

"Mike Keown" wrote in news:b64Zb.30$ snipped-for-privacy@news.uswest.net:

Just had a lok in my copy of Project Cancelled.

That states that Miles studied bullets when looking at the design for the M52.

As the X1 was based on a lot of the research done for this, it would suggest that this was correct - if indirectly :-)

Reply to
Peter Baxter

at what altitude was this P-47 pilot when he started his power dive jim do you suppose? i recall the spitfire that lost its prop' in a dive that was thought to be at about 550 to 590 mph from was it 40,000ft was it in 1945. if the P-47 [and it would have to be a late series P-47D or M i guess to have the power and boost] would probably go very fast in a dive from 30,000ft steeply. as high speed [600mph] was not a speed people had been at, going at 550mph and over felt supersonic to the USAAF pilots of the day.

trevor

Reply to
87015

We have to watch the difference between indicated and true airspeed in this thread. Dynamic pressure relates to ambient static pressure and temperature, which both vary at altitude. WW2 planes did not have sophisticated air data computers, so their airspeed indicators read only indicated airspeed. In a dive it would be too hard to keep up with computations, even with the computers (circular slide rules) pilots of those days used to find true airspeed.

87015 wrote:
Reply to
Don Stauffer

"Don Stauffer" wrote in message news: snipped-for-privacy@usfamily.net...

Yes, but. The early air-data computers in the first supersonic aircraft, such as the century series fighters.. all those air data computers were analog computers and they didn't have any trouble making the correction to get mach number from a pitot tube readings. There's no "keeping up" in analog computers -- the computation is effectively instantaneous. Digital air data computers don't appear on the scene until the late 70's -- if then. And even then, well into the 90's backup instruments and air data calculations are all done by specialized, mostly mechanical, analog calculating devices built into the instruments. Early digital air-data computers were analog-digital computers, known as DDA's -- Digital Differential Analyzers. They do analog computions digitally. A true, stored program digital computer, would indeed have had trouble "keeping up." But we computer engineers, back then, were pretty darned smart and knew how to avoid such problems -- even with our slide rules. About slide rules -- circular. These were used by pilots for navigation purposes. Mostly in the form of a specialized kind of slide-rule/plotter device. Still used by some pilots. Pilots never attempted to correct their instrument readings by using a slide rule in the cockpit -- would have laughed had it been suggested. As for computers in "those days" .. while pretty paltry by today's standards, mostly analog and (the few) digital computers were pretty darn powerful when used correctly. They didn't have to contend with the gigabytes of bloatware and obscenely obese operating systems that dominates today's computation.

Not only must airspeed be corrected, but also altitude, etc. The reason WW2 aircraft didn't have the "sophisticated" analog air data computers was because there was no need to have them. At subsonic speeds of at best 450 mph, the corrections are small.

Reply to
Boris Beizer

You need to flip over your E6B Flight Computer. Yes, one side is used for navigation, (heading & speed correction, basically), but the other is a circular slide rule. That's all, a circular slide rule, used for all sorts of calculations, including airspeeds.

Reply to
famvburg

Having done some airspeed calibration work for a modern machine, I can attest that it's still pretty much a guess - and educated guess, but a guess none the less. Digital computers have replaced the cams in the ADC, but an individual still looks over the data and then selects curves based of what that individual gathers in most "correct" as a function of ratios vs gatherable air data.

And - I happen to have such a circular slide rule for calculating Mach (vice navigating, though I also have one of those); referred to as a "Mach Wheel" by the folks that gave it to me.

AND - my E6B (that circular nav slide rule you referrd to that has been around since at least the '40's) DOES have scales for computing TAS from indicated based on compressibility and OAT, so pilot's may have laughed at the suggestion, but they still had the ability to perform the calulations in the cockpit if they cared to...which I'll bet that they did as a matter of routine in the bomber squadrons and on long-legged, high altitude mission. However "slowly" they were travelling.

Reply to
Rufus

Yeah...what famvburg said...

Reply to
Rufus

Reply to
Don Stauffer

Am Thu, 19 Feb 2004 09:53:58 -0500 schrieb "Mike Keown":

As well as the X-1 has a 'bullet-like' shape, so it differs significantly compared to that of a .50BMG bullet. But as to begin with, the choice of a fuselage shape comparable to a high-speed bullet (that already proved to be able to exceed Mach-1 :-) was not the worst at all.

But MUCH more interesting is the VERY similarity in shape (or some evolutionary similarity?), if the .50BMG bullet on one side, and the X-1 on the other side are compared to an A-4/V2 rocket, if you leave away the fins. And the A-4 was the first LARGE object similar in size to an airplane, that had an already proven supersonic design.

cu, ZiLi aka HKZL (Heinrich Zinndorf-Linker)

Reply to
spam-trash

thanks jonathan. this was the story i was thinking of. didn't a picture of this get printed in one of the 'spitfire at war' series of books?

t.

Reply to
87015

FWIW There is a chapter and several pictures on this in "Spitfire, the History" by Shacklady.

Bill Shuey

Reply to
William H. Shuey

Indeed. I don't know about the"Spitfire at War" series, I don't have them all, but as well as the Morgan & Shacklady, I have the same picture in the Putnam book on Supermarine and in "Farnborough The Story of RAE", by Turnhill & Reed. The latter goes on to say that Sqn Ldr Martindale was less fortunate on a later high speed flight when the supercharger of the replacement Spitfire burst at over 600 mph and caught fire. With the airfield clouded over he had to make a forced landing, but high tension cables forced him to crash land in a wood. He managed to jump clear and even retrieve the recording camera from the burning aircraft, but the spinal injuries he received put an end to his test flying career. Jon.

Reply to
Jonathan Stilwell

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